1. Technical Field
The field generally relates to 3D modeling.
2. Background
Computer graphics applications can render three-dimensional (3D) models representing real world objects. These real world objects can include geographical locations. Some locations can be large with many detailed features, including natural landmarks and man-made structures. 3D models representing such structures can be combined with geo-specific information for use in a geographical information system (GIS), such as Google Earth available from Google Inc.
Geo-specific 3D models may also be developed from images showing the structures to be modeled. These images may include oblique images, or images taken with a camera tilted at an angle relative to the surface of the earth or a target structure. For example, aerial pictures of city buildings and landmarks can be taken from different angles above a city such that the sides of the buildings and landmarks are captured. These images may be used to texture the surfaces of 3D building models to give a realistic look to the 3D building models. For example, 3D building model 110 is shown in display view 100 of FIG. 1. FIG. 2 shows an exemplary rendering 3D model 210 of building 110 in display view 200 that illustrates the polygon surfaces that are used to construct the 3D model of the building.
However, systems that develop 3D building models often generate excess polygon surfaces within the 3D building models. These faces are hidden from view and unnecessarily use up memory, processor and network bandwidth resources. For example, FIG. 3 shows hidden faces in 3D building model 210, such as faces 310 and 312 shown in display view 300.